During tile manufacture of an electrical cable by means of continuous extrusion, an inner conductor wire such as of copper, aluminium, steel or other electrically conductive material is coated with an insulating material of plastics, rubber and the like, the coating being applied as by extrusion from an extruder through which the inner conductor is passed at a predetermined speed.
The finished product coming from the extruder then undergoes a cooling process which cools the hot plastics or rubber coating issuing from the hot extruder whereafter the product is wound onto a drum or reel.
To preserve the electrical and mechanical characteristics of the cable, it is important that the inner conductor is located along the central axis of the cable.